diff --git a/tests/manage/task_spec.lua b/tests/manage/task_spec.lua
index 76c91e5..e172100 100644
--- a/tests/manage/task_spec.lua
+++ b/tests/manage/task_spec.lua
@@ -5,7 +5,8 @@ describe("task", function()
   local plugin = { name = "test", _ = {} }
 
   local done = false
-  local error = nil
+  ---@type string?
+  local error
 
   local opts = {
     on_done = function(task)